1992/11/09 Caterpillar

New 690 Main Rotor Lamination For 3500 SR4 Power Generators{4457}

Usage:

3500 SR4 (5UA1672-Up),
(6NA2583-Up),
(5TD1075-Up),
(6PA1646-Up) Power Generators

The new 690 Rotor assembly has replaced the 680 rotor in all 680 frame generators. The 690 rotor is effective as of September 1991. The advantages of the new 690 rotor are as follows:

1. The new lamination design uses full rectangular winding window area for maximum copper wire fill.

2. The air vent spacing was increased in the coil extension area to allow better heat transfer and cooling.

3. The support bar design was modified to secure bars for better overspeed capability.

4. The air gap has been reduced resulting in lower excitation current, lower rotor temperatures and improved heat transfer.

The new design provides better motor starting and higher efficiency.

The following charts show generator part numbers and rotor rewind data.

Caterpillar Information System:

1992/11/09 New Liner Seat Inserts Available{1217}

1992/11/09 Oil Holes In Crankshaft Main And Rod Journals{1202}

1992/11/09 Improved Fuel Injection Line Assemblies And Clamps Used{1252}

1992/11/09 Replacement Governors For Early Engines{1264}

1992/11/09 Relay Replacement Kits Available To Replace Relays In Engine Mounted Junction Box{1423,1422}

1992/11/09 Correct Identification Of Rocker Arm Assembly Components{1123}

1992/10/26 3406 Truck Engine Component Update{1052,1119,1201,1202,1205,1214,1218,1254,1288,1803}

1992/10/26 Improved Windshield Wiper Motor Crank Assemblies Available For Parts Service{7305}

1992/10/12 Improved Hour Meters (Electric){7450,7480}

1992/10/05 Product Support Literature{0374}

1992/10/05 New Cylinder Head Groups Provides Lower Valve Guide Temperatures{1100,1104,1112,1123}

1992/10/05 Thicker Head Gaskets Available For Use With Resurfaced Cylinder Blocks{1124}

1992/11/16 New Connecting Rod Assembly Used{1218}

1992/11/16 New Spacer Plate Gasket Provides Improved Sealing Around Push Rod Compartment{1221}

1992/11/16 New Cylinder Head Gasket, Spacer Plate And Head Bolts Used; New Cylinder Liner Projection Measurement Method; New Cylinder Head Torque Sequence{1124,1221,1216}

1992/11/23 New Gasket And Plate Used In Front Housing Group To Help Prevent Oil Leaks{1151}

1992/11/23 Supplemental Coolant Additive Requirements{1352,1395,1063}

1992/11/23 Procedure For Seating The Ball In The Fuel Return 4L8546 Check Valve{1274}

1992/11/23 New Service Seal Used In Altronic III Magnetos{1552}

1992/11/23 Be Sure To Use Correct Cup Plugs On 0R2077, 0R2554, And 0R3258 Remanufactured Short Blocks{1200,1201}

1992/11/23 Oil Filter Group Improved{1318}

1992/11/30 Reporting Incidents{0337}

1992/11/30 New Cylinder Head Gasket Used{1124}

1992/11/30 New Unit Injector Sleeve Used In Cylinder Head Groups{1125}